Self-propelled robotic pool cleaners include one or more drive motors to move or otherwise propel the cleaner over a surface of a pool being cleaned. The movement of the cleaner can be random or preferably is in accordance with a predetermined cleaning pattern. An electronic controller with memory is provided on the robotic pool cleaner for storing and executing cleaning programs, as well as other information to enable efficient cleaning of the pool.
The pool cleaner receives power from an external power supply via a floating power cable having a pair of conductors. Typically, the external power supply is fabricated from light-weight, buoyant corrosion-resistant materials, e.g., polyvinylchloride (PVC), polypropylene, among other well-known thermoplastic materials, aluminum and/or alloys thereof, and/or combinations thereof, and/or other corrosion resistant, water impermeable materials. The power supply is configured to be portable so that an end-user can easily move the power supply from a remote storage area to a location in close proximity to the pool so that the cleaner is free to operate without straining the power cable. As a further convenience, many pool cleaner manufacturers provide a handcart which is configured to transport the cleaner, the cable and the power supply to and from the pool.
The external power supply includes an internal power transformer and/or switching circuitry to enable operation from a conventional wall outlet or socket (e.g., 120 VAC (alternating current voltage) which is readily available at the end-user's residence or other facility. The transformer and/or switching circuitry converts the AC power from the conventional wall socket to a direct current voltage (VDC) output signal at a relatively lower voltage that is sufficient to operate the drive and/or pump motor(s) and control the pool cleaner during its cleaning operation.
The pool cleaner power cable is typically fabricated from two wire conductors having sufficient length to enable the cleaner to move over the entire bottom surface of the pool. The conductors have a protective covering that is typically fabricated from a foamed polymeric material that is buoyant and enables the cable to float as the submerged cleaner moves over the bottom and, optionally, the sidewall surfaces of the pool.
The power supply provides electrical power to drive one or more motors that propel the cleaner over the pool surfaces. For example, the one or more motors can rotate the wheels, roller brushes, and/or tracks via a transmission assembly. Alternatively, a pump motor having one or more propellers can be used to discharge a pressurized stream of filtered water in the form of a water jet that also propels the cleaner in a direction opposite the water jet. Some of the power from the power cable can also be directed to an onboard controller which includes a microcontroller, logic circuitry and/or software programs to control the movement of the cleaner.
It would be desirable if the power supply were capable of communicating with the pool cleaner. For example, initiating diagnostic tests of the pool cleaner from the power supply and then receiving signals indicating the status of various operations and components could be used to properly maintain the cleaner and improve cleaning performance and operations. Cleaner status reports, i.e., data in the form of signals, from diagnostic tests can be used to initiate visual/audible alarms to alert the user of malfunctions occurring in a drive motor, pump motor, electronic circuitry, or the like.
Because the cleaner does not have its own power source and the power cable is typically a two-wire cable, communications are limited between the power supply and the pool cleaner. One option is to send communication signals over the two-wire cable in the form of pulsed power signals. However, such pulsed power signals can cause the drive motor(s), cleaner logic and support circuitry of the cleaner to intermittently lose power, as well as lose their ground reference in the cleaner.
A three-wire cable can be utilized to provide full-duplex communications to send communication signals without the power interruptions and ground reference losses; however, such three-conductor cables are significantly more expensive than two-wire power cables.
It is desirable to provide communication signals between two electronic devices over a two-wire power cable, where one of the devices has an internal power source and the other device does not. It is further desirable to provide communication signals between an external power supply and a self-propelled robotic pool cleaner over a two-wire power cable, where the robotic pool cleaner does not have an internal power source, but receives power from the external power supply. It is further desirable to provide communication signals from the external power supply to a self-propelled robotic pool cleaner while maintaining uninterrupted power to the cleaner. It is also desirable to provide communications over a two-wire cable between the power supply and the cable, and also to enable control of the pool cleaner programming from the control circuitry of the power supply.